body{
    background-color: red;
    color: white;
}
#tupian{
    background-image: url("../images/800.jpg");
    width: 800px;
    height:372px;
    transform: rotate(45deg);
    box-shadow: 1px 1px  0 rgba(0,0,0,.25);
}
#aaaa{
    background-color: red;
    color: white;
}